Mineral composition of sour passion fruit cultivated under irrigation with saline water and potassium fertilization

Composição mineral de maracujazeiro-azedo cultivado sob irrigação com águas salinas e adubação potássica

ABSTRACT

Salt stress is one of the main abiotic factors responsible for limiting agricultural production worldwide, especially in regions with a semi-arid climate, where climatic conditions intensify the effect of salts on plants. The objective of this study was to evaluate the mineral composition of sour passion fruit plants grown under irrigation with saline water and potassium fertilization in a semi-arid region of Brazil. The experiment was carried out under field conditions in São Domingos, PB, Brazil. A randomized block design was adopted, in a 5 × 4 factorial scheme, with five levels of electrical conductivity of irrigation water - ECw (0.3, 1.1, 1.9, 2.7 and 3.5 dS m^-1) and four potassium doses - KD (60, 80, 100 and 120% of the K₂O recommendation) with 3 replicates. There was an increase in sodium and chloride contents in the stem and leaves of sour passion fruit plants with the increase in ECw levels. Fertilization with 120% of the K₂O recommendation associated with irrigation using water with EC of up to 1.1 and 1.6 dS m^-1 increased potassium content in the stem and leaves and leaf nitrogen content, respectively, in ‘BRS Sol do Cerrado’ sour passion fruit plants. Fertilization with 60% of the K₂O recommendation increased phosphorus content in the leaves of sour passion fruit plants under water salinity of up to 2.2 dS m^-1. In the leaves, nutrient contents varied according to the order of concentration N>Cl>P>Na>K, while in the stem the order was N>Cl>P>Na>K, at 160 days after transplanting.

Keywords:
Passiflora edulis Sims; Ionic absorption; Salt stress; Osmoregulation